Processed marine towed magnetometer data, Mar del Plata Canyon, SW Atlantic Ocean (FKt250712, 2025)

The data set presents the processed towed magnetometer data collected with a Marine Magnetics SeaSpy2 instrument during the 2025 Underwater Oases of the Mar del Plata Canyon (Talud Continental IV) project on R/V Falkor (too), survey FKt250712. The data files are in ASCII comma-separated format. Column headers describe the content of the files. Each record includes:Reading ID, UTC timestamp, Sampling frequency (Hz), Sensor depth (m), Latitude and longitude (decimal degrees), UTM Easting and Northing (m), Total magnetic field (nT), Diurnal magnetic correction (nT), International Geomagnetic Reference Field (IGRF, nT), Calculated magnetic anomaly (nT). The data values are referenced to the WGS 84 geographic datum. Geographic coordinates are provided as latitude and longitude (decimal degrees). Projected coordinates are provided in UTM using the appropriate zone for each survey line. Three survey lines are referenced to UTM Zone 21S, while one survey line is referenced to UTM Zone 22S. Navigation was obtained from the vessel GPS and synchronized with the magnetometer acquisition. The PILAR files contain the one-minute geomagnetic data from the PILAR observatory that was used to calculate the diurnal variation. In addition to the PILAR total field values, the files also contain the corresponding variation relative to the mean value. These PILAR values correspond to the reference geomagnetic variation used during processing. The magnetic anomaly was calculated by applying the diurnal magnetic correction to the measured total magnetic field and subtracting the International Geomagnetic Reference Field (IGRF). As part of the quality control procedure, a small number of obvious spurious measurements (extreme outliers) were identified by visual inspection and removed manually prior to data release. Data quality may also be be affected locally by vessel maneuvers, magnetic noise from the platform, or transient navigation artifacts. No additional filtering or interpolation has been applied.